*/
  @CanIgnoreReturnValue
  @Override
  public boolean offer(E e) {
    if (e == null) throw new NullPointerException();
    Monitor monitor = this.monitor;
    if (monitor.enterIf(notFull)) {
      try {
        insert(e);
        return true;
      } finally {
        monitor.leave();
      }
    } else {
      return false;
    }
  }

  /**

   *
   * @since 27.0
   */
  @ForOverride
  protected void doCancelStart() {}

  @CanIgnoreReturnValue
  @Override
  public final Service startAsync() {
    if (monitor.enterIf(isStartable)) {
      try {
        snapshot = new StateSnapshot(STARTING);
        enqueueStartingEvent();
        doStart();
      } catch (Throwable startupFailure) {

   *
   * @since 27.0
   */
  @ForOverride
  protected void doCancelStart() {}

  @CanIgnoreReturnValue
  @Override
  public final Service startAsync() {
    if (monitor.enterIf(isStartable)) {
      try {
        snapshot = new StateSnapshot(STARTING);
        enqueueStartingEvent();
        doStart();
      } catch (Throwable startupFailure) {

   * methods that do not take an explicit timeout value, a single test case is generated only if the
   * implicit timeout of that method matches the given timeoutsToUse. For example, enter() is
   * treated like enter(MAX, MILLIS) and tryEnter() is treated like enter(0, MILLIS).
   */
  private static void addTests(
      TestSuite suite,
      Method method,
      Scenario scenario,
      TimeoutsToUse timeoutsToUse,

    /** Constructor for use by subclasses. */
    public Listener() {}

    /**
     * Called when the service initially becomes healthy.
     *
     * <p>This will be called at most once after all the services have entered the {@linkplain
     * State#RUNNING running} state. If any services fail during start up or {@linkplain
     * State#FAILED fail}/{@linkplain State#TERMINATED terminate} before all other services have

    /** Constructor for use by subclasses. */
    public Listener() {}

    /**
     * Called when the service initially becomes healthy.
     *
     * <p>This will be called at most once after all the services have entered the {@linkplain
     * State#RUNNING running} state. If any services fail during start up or {@linkplain
     * State#FAILED fail}/{@linkplain State#TERMINATED terminate} before all other services have

 * therefore every method of the listener will be called at most once. N.B. The {@link State#FAILED}
 * and {@link State#TERMINATED} states are terminal states, once a service enters either of these
 * states it cannot ever leave them.
 *
 * <p>Implementors of this interface are strongly encouraged to extend one of the abstract classes

 * therefore every method of the listener will be called at most once. N.B. The {@link State#FAILED}
 * and {@link State#TERMINATED} states are terminal states, once a service enters either of these
 * states it cannot ever leave them.
 *
 * <p>Implementors of this interface are strongly encouraged to extend one of the abstract classes

  public <T> T[] toArray(T[] a) {
    Monitor monitor = this.monitor;
    monitor.enter();
    try {
      return q.toArray(a);
    } finally {
      monitor.leave();
    }
  }

  @CanIgnoreReturnValue // pushed down from class to method
  @Override
  public String toString() {
    Monitor monitor = this.monitor;
    monitor.enter();
    try {
      return q.toString();
    } finally {

    withLock {
      while (headersQueue.isEmpty() && errorCode == null) {
        val doReadTimeout = callerIsIdle || doReadTimeout()
        if (doReadTimeout) {
          readTimeout.enter()
        }
        try {
          waitForIo()
        } finally {
          if (doReadTimeout) {
            readTimeout.exitAndThrowIfTimedOut()
          }
        }
      }